Fatty acid binding proteins1/2 and their correlation with renal doppler ultrasound resistive index as predictors of diabetic kidney disease in T2DM patients

Abstract Background Diabetic kidney disease (DKD) is a leading cause of chronic kidney disease and end-stage renal disease worldwide. Fatty acid-binding proteins (FABP1 and FABP2) have emerged as potential biomarkers of renal injury. This study aimed to evaluate serum FABP1 and FABP2 levels and their association with renal Doppler resistive index (RI) in predicting DKD among patients with type 2 diabetes mellitus (T2DM). Methods This case-control study included 117 participants classified into three groups: healthy controls ( n = 39), T2DM patients without DKD ( n = 39), and T2DM patients with DKD ( n = 39), according to KDIGO guidelines. Serum FABP1 and FABP2 levels were measured using ELISA. Renal Doppler ultrasonography was performed to assess intrarenal resistive index. Receiver operating characteristic (ROC) curve analysis was used to evaluate diagnostic performance. Results Serum FABP1 and FABP2 levels were significantly higher in DKD patients compared to both diabetic patients without DKD and healthy controls ( p < 0.001). The resistive index was also significantly elevated in DKD patients (0.832 ± 0.053 vs. 0.656 ± 0.037 and 0.6 ± 0.007, p < 0.001). FABP1 at a cutoff ≥ 3.72 ng/dL showed an AUC of 0.946 with 92.3% sensitivity and 83.3% specificity for detecting DKD. FABP2 at a cutoff ≥ 0.195 ng/dL demonstrated an AUC of 0.955 with 97.4% sensitivity and 80.8% specificity. The resistive index showed highly significant diagnostic performance (sensitivity 100%, specificity 97.4%). A significant positive correlation was observed between RI and both FABP1 ( r = 0.274, p = 0.003) and FABP2 ( r = 0.239, p = 0.01). Conclusions FABP1 and FABP2 were significantly associated with renal hemodynamic changes and demonstrated promising diagnostic discrimination in this cohort. Their combination with renal Doppler resistive index may provide complementary information for DKD assessment in patients with T2DM.